Modern vehicles are equipped with an ignition lock arrangement which is arranged in the area of a dashboard or a center console of the vehicle and typically has a keyhole for receiving a vehicle key. In this context, a vehicle key can assume at least two different positions in the keyhole, one of the positions representing a vehicle state “ignition on” and the other position representing a vehicle state “ignition off”. If the key is in the “ignition on” position, a drive assembly of the vehicle together with a generator is switched on which then drives the vehicle. If the drive assembly is switched on, the generator generates electric current and feeds an on-board power system of the vehicle with this current. If, however, the key is in the “ignition off” position, the drive assembly together with the generator is switched off. In this switched-off state, the generator does not generate any current for the on-board power system. The term “ignition lock arrangement” also means generic arrangements such as, for example, a button for “start/stop”.
The modern vehicles are also equipped with various electronic systems which, in combination, are called “(vehicle) assistance system” and perform different vehicle-safety-related and comfort functions. These systems operate in normal operation and perform assigned functions completely as long as the drive assembly is switched on and the generator feeds current into the on-board power system. As soon as the drive assembly is switched off and the generator no longer feeds current into the on-board power system, the electronic systems are switched off or switched into a rest phase in which the safety of the vehicle can no longer be guaranteed completely.
Modern vehicles are also equipped with an electrical steering wheel locking arrangement which unlocks a steering wheel of the vehicle when the vehicle key in the keyhole changes from the “ignition off” position into the “ignition on” position, i.e., when the vehicle key has been authenticated positively, and locks the steering wheel when the vehicle key changes from the “ignition on” position into the “ignition off” position, i.e., when the vehicle key is taken from the keyhole. If the electrical steering wheel locking arrangement locks the steering wheel, the vehicle becomes no longer steerable and thus not controllable.
Since the ignition lock arrangement, together with the keyhole, is in an area of a dashboard or of a center console of the vehicle where there are also many operating elements such as, for example, operating elements of a navigation system or of air conditioning control, it may happen that the vehicle key, which is located in the keyhole, is accidentally touched by the driver or another passenger of the vehicle and is thus switched from the “ignition on” position into the “ignition off” position.
It may also happen that due to errors in the electrical systems of the vehicle control or in the signal connections between the electrical systems, a signal is falsely generated or detected which is indicative of the position of the vehicle key in the “ignition off” position, although the vehicle key is in the “ignition on” position.
In consequence, it may happen that the electrical systems are falsely switched off and the steering wheel is locked by the electrical steering wheel locking arrangement.
If, however, the vehicle is in a driving mode on a street, an above-mentioned accidental switching over of the vehicle key or an above-mentioned faulty signal can lead to an accident because the vehicle safety-related systems are switched off and the steering wheel is locked and the vehicle thus becomes no longer steerable.